Pump



June 1, 1948. A. H. WINKLER FUN? ' Filed Nov. 30, 1944 4 1 M my /0 0 IW. z 0 A W. M V x z W 6 ,0 w 6 M m y m av x W J w W. fl fl 1 W w. a J, H3 w l u m x d f W Wv 5 by #45527 H Mme? ATI'QRIVEY Patented June 1, 1948Aibert H. Winkler, South Bend, Ind,

'- arts Bendix Aviation commute, South Be, a. a corporation of DelawareApplication November 30, 1944, Serial No. 585,933

8 Claims. (Cl. 103-227) 1 This invention relates generally to fluidpumps and has particular reference to positive displacement pumps. Thisapplication has subject mat-- ter in common with applicants co-pendingapplication Serial No. 500,893, filed September 2, 1943, the presentinvention being an improvement over the type of pump shown in Figures 5,6 and 7 of said copending application.

While the invention in its broader aspects may i be incorporated inpumps of various types and for various purposes it is shown anddescribed herein incorporated in pumps of the positive pressure type forsupplying fuel to charge forming devices or the like. In pumps of thischaracter considerable difilculty has been encountered in eiiectingfilling or priming of the pump chamber or chambers when the pump isstarted empty and it is therefore an important object of the presentinvention to provide a pump wherein rapid filling of the pump chamber orchambers may be automatically effected when the pump is started empty.

Another object of the invention is to provide a After consideringthisexample, skilled persons will understand that many variations may bemade without departing from the principles disclosed, and I contemplatethe employments of any structures, modifications or modes of operajtionthat are properly within the scope of the appended claims.

. In the drawings:

Figure l is a diagrammatic view of a pump embodying the presentinvention; and

Figure 2 is a section taken on line 2-2 of Figure l.

Referring to the drawings there is disclosed, for the purpose ofillustrating the present invention, a reciprocating type of pump whichincludes a body portion having a. cylinder I2 in which a piston orpumping chamber I4 is reciprocably disposed. The piston may bereciprocated by any suitable means, the means herein shown, by way ofexample, comprising a shaft I8 joumalled in the body portion In of saidshaft and having a portion ll of reduced size eccentric relative to theaxis of the shaft IS. The extension I! is disposed ln the cross bore ofa block 20 slldable in a bore 22 in the piston i6 and at right angles tothe axis thereof.

Fuel is supplied to the pump "by fuel supply conduit 24 from a suitablesource of fuel, said conduit being connected with a fuel inlet 26 of thepump, the fuel passing into the interior of the cylinder by way of aport 28 of such size and so located as to be in constant communicationwith an opening 80 into the cross bore 22 from which it passes into thechamber-like portions 3| at the opposite ends of the piston by way ofports 32. Both ends of the piston ii are closed by walls 34. The pump isof the doubleacting type andinasmuch as each side is constructed, andoperates in the same manner, a

, description will be given herein of but the left hand side, as shownin the drawings. The wall or head of the piston 34 is provided with fuelpassages 30 and the flow of fuel from the interior oi the piston throughsaid passages 36 into a chamber 38 is controlled by an inlet check valve40 which comprises a rigid plate member 42, preferably of metal,attached to a valve stem 44 which extends into the piston and issubstantially coaxial therewith. The plate member 42 carries a sealinggasket 48 (of neoprene or other suitable material) having a peripherallyinturned portion 41 adapted to engage the outer surface 01' the pistonwall or head 34 encompassing the area thereof containing the ports 35. Aconical spring 48 is secured to the valve stem 44 adjacent the free endthereof and reactsbetween the point whereat it is secured to said stemand the interior surface of the piston wall or head 34 thereby normallymaintaining the valve in the closed position and preventing flow of fuelinto chamber 38. An outlet check valve, generally indicated at 50, isprovided and comprises a cup-shaped member, which is of rigid material,preferably metal. The member 5| has an outwardly extending flange 52about the open,

of a rivet 59. there being a reinforcing plate till secured by saidrivet on the side of the diaphragm opposite the valve 50. It is to benoted that the marginal edge portion of the plate is turned laterallyaway from the diaphragm to protect the latter from being cut orotherwise injured by the edge of said plate. The diaphragm is marginallysecured between the end ofthe body member [0 and a cap 84 therebyforming an expansion chamber 66 which may be considered as extendingbetween the valve seat Si and the diaphragm 58 and posterior to thechamber 38. The cap 64 is cup-shaped to provide, a spring chamber 68 3in which is disposed a calibrated spring 18 adapted to react between theouter end or bottom wall of said cup and the plate 88 for urging thevalve 88 closed. If desired the chamber 88 may be in communication withthe atmosphere by means of passages 12 and 14. Alternatively the chamber88 may be connected with an air scoop, supercharger'or the like in whichcase the passage 18 is suitably connected therewith by means of aconduit 18. The purpose of such an arrangement is to properly balancethe valve 88 at all times and therefore the relative fuel pressure isunaffected by changes in pressure occurring at the inlet opening. of thecarburetor. bein supplied with fuel by the pump.

In the arrangement herein disclosed the closed end portion of the valve88 is so positioned and the stroke of the piston is of such length thatthe head 18 of the valve stem 88 of the inlet valve will engage the head88 of rivet 88 as the piston approaches the outer limit of its strokeand when said piston has reached said outer limit the valve 88 will beslightly unseated. The pump is also provided with a fuel outlet 82connected with the expansion chamber 88 by a passage. said outlet 82being connected with a discharge conduit 88 which leads to thecarburetor or any other device to be supplied with fuel.

Operation The pump is operable independently of the direction ofrotation of the drive shaft i8. it bemain in chambers 38 and 88 and noadditional ing of the double-acting. positive displacement type. Uponrotation of the shaft IS the piston I4 is reciprocated in the cylinderl2 and, assuming that the pump is full of fuel. said fuel during theintake stroke of the piston is drawn into the inlet 28 and passesthrough the port 28 and pasvalve 88 is closed during the intake stroke,and

the inlet check valve 48 opens to permit the passage of fuel therepast.When the piston reaches the end of its intake stroke the inlet valve 88is closed by the spring 88 and as the piston moves through its dischargestroke the pressure of said piston transmitted through the fuel inchamber 88 forces the outlet check valve 50 open, discharging said i'uelinto the chamber 86 and thence through passage 88, outlet 82 anddischarge conduit 88. The device will operate as above described as longas the outlet is unrestricted. Under such operating conditionsthediaphragm 88 will be forced outwardly a very limited extent againstthe resistance of spring '10. Should the outlet be partially restrictedso that there is but a limited discharge of fuel the pressure developedin chambers 88 and 88 force the diaphragm 88 further to the left duringthe discharge stroke of the piston, the outward movement'of thediaphragm effecting an enlargement of chamber 88 sufficient to take careof the difference in normal decrease in the volume of chamber 38 and thequantity of fuel discharge per stroke of the piston. Inasmuch as theoutlet valve is controlled by the movable wall or diaphragm 88 thequantity of fuel drawn into the pump by the intake stroke of the pistonwill depend on the quantity of fuel in chambers 38 and 88. For example,should the outlet of the pump be restricted so that but one half of themaximum capacity thereof be disa fuel will be drawn into the pumpcylinder until the piston has travelled through the initial half of itsintake stroke during which the excess fuel in chambers 38 and 68 will bereturned to the cylinder under the force of spring 18. When this excessfuel has been returned to said cylinder the diaphragm has reached aposition whereat the valve III is closed. Thereafter said valve providesan inflexible end wall for the cylinder and further movement of thepiston on its intake stroke will draw more fuel into the pump. Shouldthe flow from the outlet 82 be entirely out off the diaphragm 88 wouldmerely oscillate back and forth so as to maintain the volume trapped inchambers 38 and 88 constant notwithstanding the 'is anterior to theexpansion chamber 88 and that the position of the diaphragm controls theposition of said check valve 58. the position of said diaphragm being.of course. determined by the quantity or volume of fuel dischargedthrough the chamber 88.

It is to be further noted that certain diiliculties may be encounteredin devices of this character when a diaphragm is used as onewall of theexpansion chamber and the fuel is drawn from a source by the pumpsuction. These difllculties arise from the tendency of portions of thediaphragm between the centrally reinforced portion and marginallyclamped portion to oscillate back and forth and prevent the building upof pressure for the discharge of fuel from the pump. and the intake ofthe fuel during the intake stroke of the piston. However, the foregoingdifllculty is overcome in the present invention by providing the largevalve 88 which forms an inflexible end wall for the chamber 38 andinsures the drawing of fuel into said chamber during the intake strokeof the piston. Otherwise during said intake stroke of the piston theabove mentioned flexible portion or the diaphragm would merely be drawntoward the retreating piston and prevent establishment of the necessarypressure differential for drawing more fuel into the pump and during thedischarge stroke said portions of the diaphragm will be forced outwardlyand there would be no discharge of fuel.

Priming Should the pump be started dry the chambers 88 and 68 would befilled with air as well as the interior of the piston and the conduitleading from the fuel supply source to the pump. Due to thecompressibility of the air, considerable difficulty would be encounteredin clearing the above mentioned parts of air. In order to overcome thisdifllculty the parts of the present invention are so constructed andarranged that, as above pointed out, when the piston approaches the endof its discharge stroke the head 18 of the valve stem 44 contacts thehead 88 of the rivet 88 and positively forces open the valve 88 alimited amount thus permitting the air compressed in chamber 88 toescape into the chamber 88 and thence through the passage 84, outlet 82and conduit 88. With this arrangement the air may be rapidly clearedfrom the parts above mentioned and fuel drawn into and discharged by thepump. It is to be further noted that it has been found that thisarrangement has no material adverse aifect on the eificiency of the pumpunder normal operating conditions.

It is thought that the invention and many of the foregoing descriptionand though said invention has been illustrated and described inconnection with but a single embodiment it will be apparent that variouschanges may be made in the form, construction and arrangement of theparts without departing from the spirit and scope of the invention orsacrificing all of its material advantages, the form hereinabovedescribed being merely a preferred embodiment.

I claim:

1. In a reciprocating pump: a cylinder having an open end; areciprocable pumping member mounted in the cylinder and having its headadjacent the open end of said cylinder; a flexible diaphragm forming onewall of an expansible chamber at the open end of the cylinder; asubstantially inflexible outlet valve carried by the diaphragmandadapted to close the open end of the cylinder and providing a secondchamber between said valve and the head of the reciprocable member; anda valvev controlled inlet passage communicating with the second chamher;said outlet valve being adapted to be mechanically engaged by thereciprocable member as the latter approaches the end of its dischargestroke and to be at least slightly unseated thereby when said memberreaches the end of its discharge stroke.

2. In a reciprocating pump: a cylinder having an open end; a piston insaid cylinder, said piston having a head; an inlet passage in said head;an inlet valve carried by the piston and controlling said passage; aflexible diaphragm forming one wall of an expansible chamber adapted tocommunicate with the inlet passage; a substantially inflexible outletvalve. carried by the diaphragm and adapted to close the open end of thecylinder and form one wall of a second chamher, said second chamberbeing between said expansible chamber and the head of the piston; saidoutlet valve being adapted to be engaged by a portion of the inlet valveas the piston approaches the end of its discharge stroke and to beunseated when the piston is at the end of its discharge stroke.

3. In a double-acting reciprocating fuel pump:

a cylinder; a pumping member reciprocable in said cylinder; a generallycup-shaped outlet valve capping each end of the cylinders and formingchambers between said outlet valve and the respective ends of thepumping member; flexible diaphragms carrying the respective outletvalves and forming walls of expansible chambers; springs urging thediaphragms in a direction to close-the outlet valves, said springs beingof predetermined calibration; and valve controlled inlet passages forthe pump; said pumping member being adapted to engage the respectiveoutlet valves as said member approaches the end of respective dischargestrokes and to efiect at least a limited positive opening of said valveswhen said pumping member reaches the end of the respective dischargestrokes.

4. In a reciprocating pump: a cylinder having an open end; areciprocating pumping member mounted in the cylinder; a flexiblediaphragm forming a wall of an expansible chamber adjacent the open endof the cylinder; a substantially rigid outlet valve mounted in saidchamber and adapted to close the open. end of the cylinde spring meansresiliently urging said outlet valve to its closed position; said'valvebeing displaced by fluid pressure during each discharge stroke 6 of saidpumping member; and a valve-controlled inlet passage for conductingfluid to be pumped to said expansible chamber.

5. In a reciprocating pump: a cylinder having an open end; areciprocating pumping member mounted in the cylinder and having a headmovable adjacent the open end of the cylinder; 8. flexible diaphragmproviding a wall of an expansible chamber at the open end of thecylinder; a substantially rigid outlet valve carried by said diaphragmand adapted to close the open end of the cylinder and providing a secondchamber between the outlet valve and the head of the reciprocatingmember; a spring urging the outlet valve to closed position, the outletvalve being displaced by fluid pressure during each discharge stroke ofsaid pumping member; and a valvecontrolled fluid inlet passagecommunicating with said second chamber.

6. In a reciprocating pump: a cylinder having an open end; areciprocating pumping member mounted in the cylinder; a flexiblediaphragm forming a wall of an expansible chamber'adjacent the open endof the cylinder; a substantially rigid outlet valve in said chamberconnected to said diaphragm and adapted to close the open end of thecylinder;.a spring urging said outlet valve to its closed position; saiddiaphragm being adapted to modify the effective force exerted on saidvalve by said spring in response to a variable fluid pressure externalof said expansible chamber; and a valve-controlled inlet passage forconducting fluid to be pumped to said expansible chamber.

7. In a reciprocating pump: a cylinder having an open end; areciprocating pumping member mounted in the cylinder; a flexiblediaphragm forming a wall of an expansible chamber adjacent the open endof the cylinder; a substantially rigid outlet valve mounted in saidchamber operatively connected to said diaphragm and adapted to close theopen end of the cylinder; 9, spring urging said outlet valve toward itsclosed position; means for subjecting the back side of said diaphragm toa source of variable fluid pressure for varying the effective force ofthe spring on said valve; and a valve-controlled inlet passage forconducting fluid to be pumped to said expansible chamber.

8. A pump comprising a pumping chamber, a reciprocable pumping member,inlet and outlet valves for said chamber, an expansible chambercommunicating with said pumping chamber and having a spring loadedmovable wall, means for subjecting the outlet side of said movable wallto its pumping stroke.

ALBERT H. WINKLER.

REFERENCES CITED The following references are of record in the' flle ofthis patent:

UNITED STATES PATENTS Number Name Date 72,820 Doane Dec. 31, 18671,535,643 Astrom Apr, 28, 1925 2,111,970 Gillen Mar. 22, 1938 2,134,782Fourness Nov. 1, 1938

